Integrated wireless distribution and mesh backhaul networks

ABSTRACT

Networks, devices and methods related to wireless networking. A wireless network using nodes that perform both distribution and backhaul functions is provided. These nodes constitute the key elements of a wireless network that would be deployed and controlled by a wireless network operator. Each node contains a distribution wireless module which is wirelessly coupled to the wireless end user device using a point to multipoint scheme. Also integrated into each node is at least one backhaul wireless module with a directional wireless antenna. Each backhaul wireless module communicates by way of a point to point wireless link with the backhaul module of one other node. The nodes in the wireless network are interconnected to form a mesh backhaul network. Because of the nature of a mesh network, data traffic can be routed around obstacles that may prevent line of site links. Furthermore, the mesh network allows dynamic routing of data traffic to avoid congestion points or downed links in the network.

FIELD OF THE INVENTION

[0001] The present invention relates to wireless communications and isparticularly applicable but not limited to networks, devices and methodsfor flexible, high capacity, integrated wireless distribution and meshpoint to point backhaul networks.

BACKGROUND TO THE INVENTION

[0002] The communications revolution of the past few years has seen anexplosion in the number of wireless devices. Cellular telephones,personal digital assistants (PDAs), laptops, and other consumer devicesare using wireless technology to provide connectivity to their users.Wireless technology is currently being used to provide voice-basedservices for cellular and PCS (Personal Communication Services)telephones, with increasing need for into building coverage. PDAs andlaptops can now access the Internet and local dedicated intranets,giving end users access to not only email but also to World Wide Webbased content. The increased demand for access to more services in morelocations imposes higher performance demands on the wirelessinfrastructure.

[0003] One major problem facing wireless networks is backhaul datatransmission. As cellular and PCS voice utilization inside buildingsincreases and as the data transfer rate provided to the end userincreases, the backhaul network feeding the localized wireless nodesgets heavily burdened. Each local wireless node servicing local wirelessend users must be fed traffic from public and/or private, voice and/ordata networks. As each end user demands coverage in more areas andhigher data throughput, the backhaul network, the network that feeds thelocalized wireless nodes that actually distribute data traffic toindividual end users, has to provide more and more data capacity.Further, as wireless data speed requirements increase, cell sizes—thearea serviced by the localized wireless nodes—must shrink. As celldensity increases, then, so does the number of backhaul nodes and linksthat are needed to feed the cells. In fact, the number of backhaul linksincreases inversely with the square of the wireless nodes' cell radius.

[0004] Because of the above, high speed, high capacity wireless networkshave generally been limited by backhaul bandwidth. Such bandwidth,previously provided by copper, optical or microwave radio links, comesat a very great cost to the operator and deployer of the wirelessnetwork. A wireless backhaul is clearly an attractive alternative.

[0005] However, network designers do face difficulties in using wirelesstechnology to link the wireless nodes (which distribute the signals to awireless end user) back to the wired network. It is desirable tomaximize the range between the wireless nodes and the wired network toprovide the operator with the greatest freedom in network deploymentlocation. However, many deployments, such as in dense urban areas, donot allow for line of sight links from all wireless nodes to the wirednetwork interface. Even if line of sight is possible, the variablepropagation performance of wireless links and the constant changes inthe nature and location of traffic demand make dedicated point to pointlinks less than optimal. In addition, hauling all links back to acentral point leads to high signal congestion at that point.

[0006] Previous attempts to remedy the above issues have met withlimited success. A number of patents assigned to Metricom, Inc. haveattempted to solve the above issues. U.S. Pat. No. 5,479,400 envisions amultipoint to multipoint system with relay nodes receiving multiplewireless signals from multiple repeater nodes. Unfortunately, the systemsuffers from the possibility of signal congestion at both the repeaterand the relay nodes.

[0007] SkyPilot Networks, Inc. (www.skypilot.com) proposes a similarmultipoint to multipoint wireless network with every subscriber nodebeing coupled to every other node surrounding it. Data can then travelacross any one of the links to arrive at the destination. Unfortunately,the performance of this type of network is highly dependent on thepresence and location of the subscriber's equipment. It suffers fromlimits to scalability—since each subscriber node is potentially aconnecting link for all traffic, each subscriber node can potentiallybecome clogged with data traffic. In addition, there are problems inseeding initial network coverage. Furthermore, there is a greaterpotential lack of privacy between subscribers since each node can becomean intercept point for network wide data leaks.

[0008] Mesh Networks, Inc. (WWW.meshnetworks.com) has taken a similarapproach with a different application and implementation in mind. An adhoc wireless peer to peer network is created using low power mobile enduser wireless devices. User devices, now mobile, become integral routingpoints for data traveling through the network. Unfortunately, thisapproach requires large numbers of end user devices in a given area towork properly. Furthermore, the unpredictable nature of the end users'presence and location, most of whose devices will form part of therouting network, makes for unpredictable and potentially unreliablesystem availability and performance.

[0009] What is therefore required is a system that mitigates thedrawbacks of the prior art and provides an improved solution. Thesolution should ideally allow flexible allocation of higher bit ratesbetween nodes and should be readily deployable in non line of sightenvironments, offering reliable service to all subscribers at each node.

SUMMARY OF THE INVENTION

[0010] The present invention provides networks, devices and methodsrelated to wireless networking. A wireless network using nodes thatperform both distribution and backhaul functions is provided. Thesenodes constitute the key elements of a wireless network that would bedeployed and controlled by a wireless network operator. Each nodecontains a distribution wireless module which is wirelessly coupled tothe wireless end user device using a point to multipoint scheme. Alsointegrated into each node is at least one backhaul wireless module witha directional wireless antenna. Each backhaul wireless modulecommunicates by way of a point to point wireless link with the backhaulmodule of one other node. The nodes in the wireless network areinterconnected to form a mesh backhaul network. Because of the nature ofa mesh network, data traffic can be routed around obstacles that mayprevent line of site links. Furthermore, the mesh network allows dynamicrouting of data traffic to avoid congestion points or downed links inthe network.

[0011] In a first aspect, the present invention provides a wirelessnetwork for providing services to a plurality of end users, the networkcomprising:

[0012] a plurality of routing nodes for routing traffic by using atleast one wireless signal, each routing node being wirelessly coupled toat least one other node;

[0013] at least one network aggregation node for routing said trafficeither between nodes in said network or between said wireless networkand another network, the or each network aggregation node being coupledto at least one routing node;

[0014] wherein at least one routing node may also perform a distributionfunction for distributing said traffic to at least one wireless end userdevice;

[0015] optional end nodes for distributing said traffic to a pluralityof wireless end user devices, each end node being wirelessly coupled toat least one other said routing or aggregation node.

[0016] In a second aspect, the present invention provides a device forreceiving and transmitting at least one wireless signal, the devicecomprising:

[0017] at least one wireless backhaul module for communicating with atleast one node in a wireless network;

[0018] a wireless distribution module for communicating with at leastone wireless end user device,

[0019] wherein the device receives said at least one wireless signalfrom said at least one node by way of the at least one backhaul moduleand transmits at least a portion of at least one of said at least onewireless signal to said at least one end user device by way of thewireless distribution module and

[0020] the or each wireless backhaul module communicates with a singlenode in the wireless network at any one time.

[0021] In a third aspect, the present invention provides a device forreceiving and transmitting at least one wireless signal, the devicecomprising:

[0022] at least two wireless backhaul modules for communicating with atleast one node in a wireless network;

[0023] a wireless distribution module for communicating with at leastone wireless end user device;

[0024] a switch/router module for routing traffic between differentmodules in said device, said traffic being extracted from said at leastone wireless signal;

[0025] wherein the device receives said at least one wireless signalfrom said at least one node by way of the at least one backhaul moduleand transmits at least a portion of at least one of said at least onewireless signal to either,

[0026] another node in the wireless network by way of the at least onebackhaul module, or;

[0027] to said at least one end user device by way of the wirelessdistribution module and

[0028] the or each wireless backhaul module communicates with a singlenode in the wireless network at any one time.

[0029] In a fourth aspect, the present invention provides a device forreceiving and transmitting at least one wireless signal, the devicecomprising:

[0030] at least one wireless backhaul module for communicating with atleast one node in a wireless network;

[0031] a switch/router module for routing traffic between differentmodules in said device, said traffic being extracted from said at leastone wireless signal;

[0032] at least one network interface module for communicating withanother network;

[0033] optionally, a wireless distribution module for communicating withat least one wireless end user device;

[0034] wherein the device receives said at least one wireless signalfrom said at least one node by way of the at least one backhaul moduleand transmits at least a portion of at least one of said at least onewireless signal to a destination selected from a group comprising:

[0035] another node in the wireless network by way of the at least onebackhaul module;

[0036] said another network by way of the at least one network interfacemodule;

[0037] said at least one end user device by way of the wirelessdistribution module and wherein

[0038] the or each wireless backhaul module communicates with a singlenode in the wireless network at any one time.

[0039] In a fifth aspect, the present invention provides a method forrouting traffic in a network from a specific node in said network, themethod comprising the steps of:

[0040] a) gathering information related to at least one link betweensaid specific node and nodes adjacent to said specific node;

[0041] b) for the or each of said links, calculating a cost associatedwith said link between said specific node and a node adjacent to saidspecific node associated with said link;

[0042] c) receiving data from other nodes in said network, said datarelating to costs associated with links between said other nodes andnodes adjacent to said other nodes;

[0043] d) distributing link data to said other nodes, said link dataincluding a cost for the or each of said links between said specificnode and nodes adjacent to said specific node;

[0044] e) determining routing paths from said specific node to each ofsaid other nodes based on said data calculated in b) and said link datareceived from other nodes in step c) such that a path cost associatedwith said routing path is minimized, wherein only most recent data areused in step e).

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] A better understanding of the invention will be obtained byconsidering the detailed description below, with reference to thefollowing drawings in which:

[0046]FIG. 1 is a top level large network block diagram illustrating anumber of subnetworks coupled to a core network;

[0047]FIG. 2 is a block diagram of a wireless subnetwork with a networkaggregation node and multiple routing nodes and end nodes;

[0048]FIG. 3 is a block diagram illustrating the modules in an end node;

[0049]FIG. 4 is a block diagram illustrating the modules in a routingnode; and

[0050]FIG. 5 is a block diagram illustrating the modules in a networkaggregation node.

DETAILED DESCRIPTION

[0051] Referring to FIG. 1, a block diagram of a large network 10 isillustrated. The network 10 consists of a core network 20 and wirelessnetworks 30, 40, 50, 60, 70, each of which has a network aggregationnode 30A, 40A, 50A, 60A, 70A. The core network 20 may be a public and/orprivate, voice and/or data network. Each wireless network covers aspecific geographic region. Each network aggregation node 30A-70Adirectly connects to the core network 20 by conventional means such ascopper wire, fiber optic cable or microwave radio transmission. Eachnetwork aggregation node 30A-70A then distributes data from the largenetwork to end users within the geographic region of the coverage of itswireless network.

[0052] Referring to FIG. 2, a block diagram of the wireless network 30in FIG. 1 is illustrated. As can be seen, the network aggregation node30A is connected to a core network as shown previously in FIG. 1. Thewireless network 30 consists of a wireless network aggregation node 30A,a number of routing nodes 80A-80S and a number of end nodes 90A-90M. Therouting nodes 80A-80S are interconnected to form a mesh network. Theconnections between the routing nodes and the end nodes are as follows:Connected to Network Routing Aggregation Node Connected to Connected toNode 30A Routing Nodes End Nodes 80A YES 80E, 80C 90A, 90B 80B NO 80D,80C 90H 80C NO 80A, 80B 90C 80D NO 80E, 80B, 80F 90D 80E YES 80D, 80G,80A 80F NO 80D, 80I, 80G 80G NO 80E, 80F, 80H 80H YES 80G, 80I, 80L, 80R80I NO 80F, 80H, 80J 90G 80J NO 80I, 80K 90F 80K NO 80J, 80L, 80M 90E80L NO 80H, 80K, 80S 80M NO 80K, 80S, 80N 90K, 90J 80N NO 80M, 80O 80ONO 80N, 80P 90I 80P NO 80Q, 80S, 80O 90M 80Q YES 80R, 80P 90L 80R YES80H, 80S, 80Q 80S NO 80L, 80M, 80P, 80R

[0053] A network aggregation node performs routing of traffic, eitherbetween nodes in the wireless network, or between the wireless networkand the core network. The network aggregation nodes terminates backhaullinks from routing or end nodes in the wireless network. Networkaggregation nodes may also perform a distribution function where thereis a need to provide service to subscribers near the aggregation point.

[0054] A main function of a routing node is to perform backhaul androuting of traffic from a source to a destination. Each routing node iscoupled to at least one other routing node (or the aggregation node) bya point to point wireless link Most routing nodes also perform adistribution function in that they communicate with end user devices,using a multipoint wireless link, to receive and distribute traffic toand from these end user devices.

[0055] End nodes, on the other hand, only receive traffic from end userdevices for transmission to a routing node (or the aggregation node) andthey distribute traffic received from routing nodes (or the aggregationnode) to end user devices.

[0056] From the above, the main functions of a routing node are asuperset of the functions of an end node. A routing node serves to routetraffic from a source, such as an end user device in the same wirelessnetwork or a node in the larger network, to a destination, again such asan end user device in the wireless network or in another network. Thetraffic is sent encoded in at least one wireless signal that istransmitted from one routing node to another in the wireless networkuntil it reaches its destination—either an end user device or thenetwork aggregation node. If the destination is the network aggregationnode, the traffic can be further routed via the core network to itsultimate destination. If the destination is an end user, the traffic isdistributed to the end user device serviced by an appropriate routing orend node. It should therefore be clear that both routing and end nodescommunicate with the end user devices and distributes the traffic whichhas been routed via other routing nodes. Both end and routing nodesreceive traffic from the end user devices that they service and transmitthis traffic to the appropriate routing or aggregation node for routingto their destination.

[0057] It should be noted that, in performing the distribution function,each routing node or end node communicates with multiple wireless enduser devices. This point to multipoint nature of the distributionfunction is in contrast to the point to point nature of the backhaulfunction of the routing node. Each wireless link between routing nodesin the wireless network is independent of any other and, due to this,each link can serve as a back up or a redundancy for the other links. Ifa wireless link between two routing nodes fails or is congested, thenetwork can adaptively re-route traffic around the blockage or thecongestion. As an example, referring to FIG. 2, if traffic destined forend node 90F originates from the network aggregation node 30A, onesequence of routing nodes that can be traversed is that of30A-80H-80I-80J-90F. However, if the wireless link between routing nodes80I and 80H goes down for any number of reasons, the traffic can bererouted to the following sequence of routing nodes:30A-80H-80L-80K-80J-90F. This can be implemented by providing eachrouting node with a table of destinations and primary and secondary nexthops for that destination. Thus, for a destination in node 90F, thetable in node 80H will have a primary next hop as node 80I with asecondary hop as node 80L and perhaps a tertiary next hop as node 80G.Each routing node thus continually checks the status of its links todetermine if they are available or not. If traffic destined for acertain destination has a primary hop that is unavailable, then thetraffic is sent to the secondary next hop or, alternatively, to atertiary next hop. The time-varying data regarding the availability ofthe links that a routing node may use are then distributed to otherrouting nodes so that each routing node may have a map of the prevailingconditions in the wireless network.

[0058] While the above explanation posits routing traffic based on theavailability of wireless links between routing nodes, other routingschemes may be used. As an example, routing schemes based on balancingthe data transmission loads between links for at least some of therouting nodes in the wireless network may be used. These and otherrouting schemes are known to those skilled in the art and should bechosen based on the circumstances surrounding each specificimplementation. Flammer III, in U.S. Pat. No. 5,488,608, incorporatedherein by reference, discloses one such routing scheme which may beused. Similarly, Flammer et al. in U.S. Pat. No. 4,939,726 and Baran etal. in U.S. Pat. No. 5,115,433, both of which are incorporated herein byreference, disclose other routing schemes which may be used.

[0059] One possible routing scheme is derived from known link staterouting techniques. This routing scheme is particularly applicable towireless networking as link state routing schemes have advantages inrobustness and convergence speed, two characteristics important forwireless networks.

[0060] For this routing scheme, each node has a router daemon whichperforms four functions:

[0061] a) The daemon greets and establishes contact with neighboringnodes by sending identifying packets to the neighboring nodes.

[0062] b) The daemon constructs and sends to each neighboring node alink state packet. Each link state packet contains theaddress/name/identifying indication of the originating node, theoriginating node's neighboring nodes, and, for each neighboring node, acost associated with a dedicated link between the neighboring node andthe originating node.

[0063] c) Each link state packet is transmitted to all the other nodesand is provided with either time stamps or sequence numbers. The timestamps and/or sequence numbers are used to ensure that the latest datais being used for any particular routing node. The daemon keeps track ofthese link state packets and ensures that the latest data is being usedfor all nodes in the network.

[0064] d) Each routing daemon in each node then continuously computesroutes to each destination within the wireless network using its ownhome node as the starting point. This calculation can be done using,among others, the well-known Dijkstra Shortest Routing Path algorithm.This and other algorithms for calculating routing paths based on costsassociated with each link may be found in texts such as “Introduction toAlgorithms”, McGraw-Hill, 1990. For optimum results, the data trafficshould be routed to a route in which the combined cost is minimal.

[0065] As noted above, a cost is associated with each link between twonodes in the wireless network. For each link, the cost can be derivedfrom:

[0066] 1) bit rate information for the link found the adaptivemodulators used at the physical layer of the link

[0067] 2) link utilization information extracted from parameters, suchas delay, measured at each node.

[0068] This cost for each link can be automatically calculated at theinitiation or startup of the link using the bit rate informationreferred to above. The cost can thereafter be updated for any changes inthe bit rate and, optionally, using link utilization information asoutlined above. These steps will provide a reasonably instantaneousindication of the cost for each link. Such time-varying information, inconjunction with the routing scheme outlined above, will allow each nodeto determine the most efficient routing path through the network for itstraffic. This time-varying information will ensure that, for any giventime period, the most efficient path will in all likelihood be used fortraffic to traverse the wireless network.

[0069] Since the backhaul links are independent point to pointconnections, the allocation of transmission capacity between the twoends of a given backhaul link can be determined between the two endsindependently of any other link. The allocation of capacity in the twodirections may be predetermined—fixed or under operator control.Alternatively a protocol can negotiate between the two ends to decide onthe flow of traffic on the basis of packets queued at each end of thelink. The number or size of the packets can be used to determine whichend is to transmit. This and other parameters of the link can benegotiated between the two ends of the link. Additionally for multimediatraffic, priority tags may be used with the packets as they are queuedand Quality of Service (QoS) management may be used to alter thetransmission order of the packets.

[0070] To improve the performance of each of the point to point backhaulconnections, interference between backhaul radios within a given routingnode should be minimized. For applications in which time division duplextransmission (TDD) is used for interleaving receive and transmit datatransmissions, the backhaul radios in a single node may be synchronized.This will ensure all radios in a single node are transmitting during thesame interval so as not to desensitize nearby backhaul radio receivers.This synchronization can be implemented by injecting a framing signalinto the protocol processors within each node. The timing of transmitpackets on all links for a particular node are then referenced by theprocessors to that framing signal.

[0071] Compared to traditional wireless networks, where links arestatically assigned, the network explained here is particularly usefulfor applications where propagation characteristics change and trafficvolumes and congestions fluctuate. Each routing node can be deployed ata street corner or rooftop where it may have a point to point line ofsight wireless link with at least one other routing node or end node.While line of sight is not necessary for a point to point wireless link,much greater data throughput and transmission spreads and/or distancescan be achieved with such links. Furthermore, while direct line of sightfrom the network aggregation node may not be possible to each and everyrouting or end node, by routing traffic from the network aggregationnode through multiple routing nodes, the range of a wireless network canbe greatly extended. As an example, if the network aggregation node 30Acan only have line of sight access to routing nodes 80A, 80E, 80H, 80R,80Q with each routing node being within 5 kilometers of the networkaggregation node, by routing traffic through the routing nodes, trafficcan reach end node 90F which may be as far as 20 km away from thenetwork aggregation node 30A.

[0072] It should be clear that for the distribution function, eachrouting or end node has a limited geographic coverage in that onlywireless end users within that geographic coverage can receive servicesfrom a particular node. Thus, wireless end user device being serviced bynode 90C cannot be serviced by node 90M. Each node therefore covers a“cell”, a geographic area in which users can be serviced by a particularnode. While cells may overlap, each node can service end user deviceswhich are in its cell. To extend the coverage of the wireless network tomultiple isolated islands, between which no coverage is required,dedicated routing nodes which only perform the backhaul function and notthe distribution function may be used.

[0073] To implement the above wireless network, FIG. 3 illustrates ablock diagram for an end node device 100. The end node device 100 has abackhaul wireless module 110 coupled to a directional antenna 120. Amultipoint distribution wireless module 130 is coupled to antennae 140A,140B. It is suggested that two antennae be used to implement spatial orpolarization diversity, thereby increasing the range of each multipointradio. The backhaul and distribution radios may use common or separatefrequency bands depending on the capacity required and the radiospectrum available. A management and control module 150 controls nodeoperation and routing functions and implements protocols such as SNMP(Simple Network Management Protocol) for network management functions. Apower supply/battery backup module 160 provides power to the end nodedevice 100. The backhaul wireless module 110 receives a wireless signalby way of the antenna 120 from a neighboring routing node. The trafficencoded in the wireless signal is then extracted and encoded for thedifferent end user devices, 175A, 175B, 175C, that are its destinations.These wireless signals are then sent to the end user devices by way ofthe multipoint distribution wireless module 130 and the antennae 140A,140B. Traffic is received by the end node from these end user devices byway of the multipoint distribution wireless modules 130 and themultipoint antennae 140A, 140B and this traffic is extracted,re-encoded, and sent to the backhaul wireless module 110 and its antenna120. This encoded traffic is then transmitted by the backhaul wirelessmodule 110 to the wireless network for routing to its destination.

[0074] Referring to FIG. 4, a block diagram of a routing node device 170is illustrated. This routing node device 170 performs both distributionand backhaul functions. As can be seen, the routing node device 170 isequipped with three backhaul wireless modules 110A, 110B, 110C withtheir corresponding directional antennae 120A, 120B, 120C. A multipointdistribution wireless module 130 and its antennae 140A, 140B, arepresent along with a management and control module 150 and powersupply/battery backup module 160. Similar to the device 100 in FIG. 3,the multipoint distribution wireless module 130 communicates with enduser devices 175A, 175B, 175C. A switch/router module 180 is coupled toall the wireless modules—backhaul wireless modules 110A, 110B, 110C, andmultipoint distribution wireless module 130. The switch router module180 routes traffic within the routing node device 170 to their properwireless module interim destinations. As an example, information intraffic received from another routing node by way of one of the backhaulwireless modules may be destined for another routing node or it may bedestined, via the distribution module, for an end user device currentlybeing serviced by this routing node. If the information within thattraffic is destined for another routing node, then the information issent to one of the other backhaul wireless modules for transmission to aneighboring routing node. If the traffic is destined for an end userdevice currently being serviced by this particular routing node 170,then the traffic is routed by the switch/router 180 to the multipointdistribution wireless module 130. Otherwise, the traffic is routed toone of the other backhaul wireless modules 110B, 110C. Thisswitch/router module 180, in conjunction with the management and controlmodule 150, would implement whichever routing scheme is chosen.

[0075] In contrast to the above description of a regular routing node, adedicated routing node is a routing node which only performs thebackhaul function and not the distribution function. It is generallysimilar to a regular routing node except for one important detail. Sincethe dedicated routing node will not be performing the distributionfunction, the dedicated routing node will not have the multipointdistribution wireless module 130 and antennae 140A, 140B. However, asidefrom this distinction, dedicated routing nodes are similar in structureand construction to regular routing nodes.

[0076] It should be noted that any wireless signal received by a routingnode (or a dedicated routing node) is first decoded to extract theaddressing information encoded within the traffic carried by thewireless signal. Then, based on that addressing information, the trafficis routed to another wireless module, either another backhaul wirelessmodule or a multipoint distribution wireless module (if present). Atthis second wireless module, the traffic is re-encoded into a wirelesssignal so it can be transmitted to either another node or an end userdevice.

[0077] A similar process is executed by each end node. Any wirelesssignal received from a routing node by way of the backhaul wirelessmodule 110 is decoded to extract the addressing information encodedwithin the traffic contained in the wireless signal. The traffic is thensent to the multipoint distribution wireless module 130 for re-encodinginto a wireless signal and transmission to the relevant end user device.Similarly, traffic received from an end user device by way of themultipoint distribution wireless module 130 is decoded and, based on theaddressing information in the traffic, sent to either the backhaulwireless module 110 (for transmitting to the wireless network by way ofa neighboring routing node) or the multipoint distribution wirelessmodule 130 (for transmitting to another end user device being servicedby the same end node).

[0078] Referring to FIG. 5, a block diagram of a network aggregationnode 30A is illustrated. As can be seen, the aggregation node device 190is again equipped with three backhaul wireless modules 110A, 110B, 110C,with their corresponding directional antennae 120A, 120B, 120C. Anoptional multipoint distribution wireless module 130 and its antennae140A, 140B, are shown in this example. A distribution module will beincluded when there is a need to provide service to subscribers near theaggregation point. Also shown are a management and control module 150and a power supply/battery backup module 160. A switch/router module 180is coupled to all the wireless and wired modules. A network interfacemodule 200 connects to the core network, using any of a variety of voiceor data network interfaces and protocols, such as Ethernet, ATM(Asynchronous Transfer Mode), or traditional TDM (Time DivisionMultiplexing) interfaces.

[0079] To minimize external interference and maximize range, thewireless signal from backhaul module 110 ideally feeds an associateddirectional antenna with a narrow beamwidth. The narrowness of thebeamwidth needs to be traded off against the need to avoid any line ofsight pointing at installation. Beamwidths of 15-60 degrees have beenfound to be a reasonable compromise between the two. Other beamwidthsmay be tried for other specific applications.

[0080] When nodes are deployed outdoors, temperature and humidityvariations and other environmental factors can wreak havoc on networkperformance. To minimize any environmental effects on the wirelessnetwork, each routing or end node which will be deployed in an outsideenvironment may ideally be weather hardened. Suitable weather resistantmeasures, such as waterproofing the casing and screening from sun andcontaminants, are advisable. The weather resistance measures may differfor different environments as nodes to be installed in a northernclimate will have to deal with significantly different weatherconditions from nodes to be installed in a desert or a tropical climate.

[0081] A person understanding this invention may now conceive ofalternative structures and embodiments or variations of the above all ofwhich are intended to fall within the scope of the invention as definedin the claims that follow.

We claim:
 1. A device for receiving and transmitting at least onewireless signal, the device comprising: at least one wireless backhaulmodule for communicating with at least one node in a wireless network; awireless distribution module for communicating with at least onewireless end user device, wherein the device receives said at least onewireless signal from said at least one node by way of the at least onebackhaul module and transmits at least a portion of at least one of saidat least one wireless signal to either, another node in the wirelessnetwork by way of the at least one backhaul module, or; to said at leastone end user device by way of the wireless distribution module and theor each wireless backhaul module communicates with a single node in thewireless network at any one time.
 2. A device according to claim 1wherein the device further comprises: at least two backhaul modules; anda switch/router module for routing traffic between different modules insaid device said traffic being extracted from said at least one wirelesssignal.
 3. A device for receiving and transmitting at least one wirelesssignal, the device comprising: at least two wireless backhaul modulesfor communicating with at least two nodes in a wireless network; awireless distribution module for communicating with at least onewireless end user device, a switch/router module for routing trafficbetween different modules in said device said traffic being extractedfrom said at least one wireless signal, wherein the device receives saidat least one wireless signal from said at least one node by way of theat least one backhaul module and transmits at least a portion of atleast one of said at least one wireless signal to either, another nodein the wireless network by way of the at least one backhaul module, or;to said at least one end user device by way of the wireless distributionmodule and the or each wireless backhaul module communicates with asingle node in the wireless network at any one time.
 4. A deviceaccording to claim 2 wherein the device further comprises at least onenetwork interface module for communicating with another network.
 5. Adevice according to claim 1 wherein the or each wireless backhaul modulecommunicates with a single node in the wireless network at any one timeusing a point to point wireless link.
 6. A device according to claim 1wherein the or each wireless backhaul module has a dedicated antenna fora point to point connection with another node in the wireless network.7. A device according to claim 6 wherein the dedicated antenna has abeamwidth of about 15-60 degrees.
 8. A device according to claim 1wherein the wireless distribution module communicates with a pluralityof wireless end user devices. 9 A device according to claim 1 whereinsaid device utilizes time-varying information to route traffic in saidwireless network.
 10. A device according to claim 9 wherein for the oreach backhaul module, said time-varying information is derived from bitrate information related to a link between said the or each backhaulmodule and the single node.
 11. A device according to claim 9 whereinfor the or each backhaul module, said time-varying information isderived from link utilization information related to a utilization of alink between said the or each backhaul module and the single node.
 12. Adevice according to claim 1 wherein for the or each wireless backhaulmodule, said device negotiates with said single node to determinetransmission parameters between said device and said single node.
 13. Adevice according to claim 3 wherein the at least two backhaul modulesare time synchronized with a framing signal such that the timing oftransmissions from any backhaul module in the device is based on saidframing signal.
 14. A wireless network for providing services to aplurality of end users, the network comprising: a plurality of routingnodes for routing traffic by using at least one wireless signal, eachrouting node being wirelessly coupled to at least one other node, atleast one network aggregation node for routing said traffic between saidwireless network and another network, the or each network aggregationnode being coupled to at least one routing node; wherein at least onerouting node also performs a distribution function for distributing saidtraffic to at least one wireless end user device.
 15. A wireless networkaccording to claim 14 wherein the wireless network further comprises: atleast one end node for distributing said traffic to a plurality ofwireless end user devices, each end node being wirelessly coupled to atleast one routing or aggregation node, each end node communicating withthe or each routing or aggregation node by way of a dedicated point topoint link.
 16. A wireless network according to claim 14 wherein said atleast one routing node performs said distribution function using awireless distribution module for communicating with said at least onewireless end user device.
 17. A wireless network according to claim 14wherein the or each network aggregation node is coupled to a corenetwork which provides at least a portion of traffic, said traffic beingencoded into said at least one wireless signal for routing to said atleast one end user device.
 18. A wireless network according to claim 14wherein each of the plurality of routing nodes is coupled to at leastone other routing node by way of a point to point wireless link. 19 Awireless network according to claim 18 wherein the plurality of routingnodes are wirelessly coupled to form a mesh network.
 20. A wirelessnetwork according to claim 19 wherein said mesh network allows trafficto be routed from one node in the network to another node, said trafficbeing encoded in said at least one wireless signal.
 21. A wirelessnetwork according to claim 14 wherein each distribution node wirelesslycommunicates with a plurality of wireless end user devices.
 22. Awireless network according to claim 15 wherein each end node comprisesat least one wireless backhaul module for communicating with at leastone node in the wireless network; a wireless distribution module forcommunicating with said least one wireless end user device, wherein eachend node receives said at least one wireless signal from said at leastone node by way of the at least one backhaul module and transmits atleast a portion of at least one of said at least one wireless signal tosaid at least one end user device by way of the wireless distributionmodule and the or each wireless backhaul module communicates with asingle node in the wireless network at any one time.
 23. A wirelessnetwork according to claim 14 wherein at least one routing nodecomprises: at least two backhaul modules; and a switch/router module forrouting traffic between different modules in said at least one routingnode, said traffic being extracted from said at least one wirelesssignal, wherein the or each routing node receives said at least onewireless signal from said at least one other node by way of the at leasttwo backhaul module and transmits at least a portion of at least one ofsaid at least one wireless signal to either, another node in thewireless network by way of the at least one backhaul module, or; to saidat least one end user device by way of the wireless distribution module24. A method for routing traffic in a network from a specific node insaid network, the method comprising the steps of: a) gatheringinformation related to at least one link between said specific node andnodes adjacent to said specific node; b) for the or each of said links,calculating a cost associated with said link between said specific nodeand a node adjacent to said specific node associated with said link; c)receiving data from other nodes in said network, said data relating tocosts associated with links between said other nodes and nodes adjacentto said other nodes; d) distributing link data to said other nodes, saidlink data including a cost for the or each of said links between saidspecific node and nodes adjacent to said specific node; e) determiningrouting paths from said specific node to each of said other nodes basedon said data calculated in step b) and said link data received fromother nodes in step c) such that a path cost associated with saidrouting path is minimized wherein only most recent data received fromsaid other nodes are used in step e).
 25. A method according to claim 24wherein for the or each link, said information is derived from bit rateinformation related to a specific link between said specific node and anode adjacent to said specific node.
 26. A method according to claim 24wherein for the or each link, said information is derived from linkutilization information related to a utilization of a link between saidspecific node and a node adjacent to said specific node.
 27. A methodaccording to claim 24 wherein said network is a wireless network.
 28. Amethod according to claim 24 wherein said specific node comprises: atleast one wireless backhaul module for communicating with at least onenode in a wireless network; a wireless distribution module forcommunicating with at least one wireless end user device; wherein thedevice receives said at least one wireless signal from said at least onenode by way of the at least one backhaul module and transmits at least aportion of at least one of said at least one wireless signal to either,another node in the wireless network by way of the at least one backhaulmodule, or; to said at least one end user device by way of the wirelessdistribution module and the or each wireless backhaul modulecommunicates with a single node in the wireless network at any one time.29. A method according to claim 28 wherein said specific node furthercomprises a switch/router module for routing traffic between differentmodules in said at least one routing node, said traffic being extractedfrom said at least one wireless signal.
 30. A wireless network accordingto claim 14 wherein the or each network aggregation node comprises: atleast one wireless backhaul module for communicating with at least onenode in said wireless network; a switch/router module for routingtraffic between different modules in said aggregation node, said trafficbeing extracted from said at least one wireless signal; at least onenetwork interface module for communicating with said another network;wherein the or each network aggregation node receives said at least onewireless signal from said at least one node by way of the at least onebackhaul module and transmits at least a portion of at least one of saidat least one wireless signal to a destination selected from a groupcomprising: another node in the wireless network by way of the at leastone backhaul module; said another network by way of the at least onenetwork interface module; and wherein the or each wireless backhaulmodule communicates with a single node in the wireless network at anyone time.
 31. A wireless network according to claim 30 wherein the oreach network aggregation node further comprises a wireless distributionmodule for communicating with at least one wireless end user device. 32.A device for receiving and transmitting at least one wireless signal ina wireless network, the device comprising: at least one wirelessbackhaul module for communicating with at least one node in saidwireless network; a switch/router module for routing traffic betweendifferent modules in said device, said traffic being extracted from saidat least one wireless signal; at least one network interface module forcommunicating with another network; wherein said device receives said atleast one wireless signal from said at least one node by way of the atleast one backhaul module and transmits at least a portion of at leastone of said at least one wireless signal to a destination selected froma group comprising: another node in the wireless network by way of theat least one backhaul module; said another network by way of the atleast one network interface module; and wherein the or each wirelessbackhaul module communicates with a single node in the wireless networkat any one time.
 33. A device according to claim 32 wherein said devicefurther comprises a wireless distribution module for communicating withat least one wireless end user device.